$(document).ready( function () {
	//when leaving the left container, make it half opaque
	$(".FirstContainer").mouseleave(
		function() {
			$(this).css("opacity","0.4");//works for FF and IE8
			//filter:alpha(opacity=40);");
		}
	);
	//when entering the left container, make it transparent again
	$(".FirstContainer").mouseenter(
		function() {
			$(this).css("opacity","1.0");//works for FF and IE8
			//$(this).css("opacity:1.0;filter:alpha(opacity=100);");
		}
	);
});